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Biomedical subjects

A Shimada

Publications and source records attributed to A Shimada.

At least 307 records · Page 17Linked to original sources
PubMed1984

[Pharmacodynamic effects of d-nicotine--Comparison with l-nicotine].

The acute toxicity and pharmacological effects of d-nicotine were examined in several species of animals and compared with those of l-nicotine. The LD50s for intravenous administration of d- and l-nicotine were 6.15 and 0.33 mg/kg, respectively. In unanesthetized rhesus monkeys, EEG activity was not influenced by d-nicotine, 64 micrograms/kg, i.v., while the same dose of l-nicotine produced seizure-like waves with some spindles. In rats, d-nicotine increased spontaneous motor activity, and in the experiment under a DRL 20-sec schedule, it increased lever press responding, decreased the number of reinforcements and shortened interresponse time. Similar effects were also observed by administration of l-nicotine at lower doses than for the d-isomer. In anesthetized rats, d-nicotine elevated the blood pressure and increased the heart rate with a potency of about one-eighth that of the l-isomer. Further, tachyphylaxis and cross tachyphylaxis were developed to the blood pressure-raising effect in rats after repeated administration of both isomers. d-Nicotine elicited contraction of isolated rat ileum preparations, but with a potency of about one-tenth that of the l-isomer. Both isomers at the same concentration blocked transmission at the neuromuscular junction in isolated rat phrenic nerve-diaphragm muscle preparations. These results indicate that the pharmacological effects of d-nicotine are qualitatively similar to but quantitatively less potent than those of l-nicotine.

Animals↗
PubMed1983

Dominant lethal mutation rate after gamma-irradiation of the fish, Oryzias latipes.

When laying females or males of the small fish Oryzias latipes were irradiated with gamma-rays and then mated with a non-irradiated partner, the fertility and hatchability of the embryos were reduced as the doses increased. In respect to hatchability (the induction of dominant lethality), the male was more sensitive than the female, and mature sperm were most sensitive among the various stages of spermatogenetic cells. The dose-rate effects on the production of the dominant lethality were observed in spermatogonia and spermatocytes. The inbred strain of the fish, HB-1, was sensitive to gamma-rays. Since the relationship between dose and the decrease in hatchability was almost linear, at least within a limited range, we think that this system would be useful for monitoring mutagenic factors in an aquatic environment.

Animals↗
PubMed1983

Chronic pancreatitis as psychosomatic disorder.

69 patients with chronic pancreatitis, which were classified as the definite type and the suspicious type, were studied psychosomatically. The comparative analysis between the two types were examined. It was concluded that the suspicious type, classified as the 'actual psychosomatic disease', was primarily related to psychosomatic factors, while the definite type, classified as 'character psychosomatic disease', was primarily related to and manifested as chronic alcohol-drinking habits.

Adolescent↗
PubMed1983

Fecal neutral steroids in two Japanese populations with different colon cancer risks.

Several workers have associated fecal neutral steroids with colon cancer frequency. They suggested that the risk for colon cancer increases with a rise in the level of total and certain neutral steroids. The Japanese in Hawaii, who are at high risk for this cancer, had a higher concentration of cholesterol and total animal steroids in their fecal specimens than did the people in Akita, Japan, who are at low risk. However, the rest of the findings on neutral steroids were unremarkable or inconsistent in comparison with those of other studies. These data are suggestive but not strongly supportive of a relationship between fecal neutral steroid patterns and colon cancer risk.

Colonic Neoplasms↗
PubMed1983

[Pharmacological studies of guanabenz. Effects on the peripheral nervous and other organ systems].

General pharmacological properties of guanabenz (GUB), a new anti-hypertensive agent, were studied in comparison with those of clonidine (CLD) and guanethidine (GUD). Intravenous or peroral administration of GUB caused a contraction of the nictitating membrane in cats and mydriasis in mice, while it produced an inhibitions of the gastrointestinal motility in dogs; the motility of isolated rabbit ileum; and chacol transport, salivation and gastric acid secretion in rats. GUB had no or slight inhibitory actions on contractile responses induced by peripheral sympathetic or parasympathetic nerve stimulation in various organs; however, it had antagonistic actions against the norepinephrine-induced contraction of isolated guinea-pig vas deferens. The contractile responses to epinephrine and tyramine in the nictitating membrane and to sympathetic nerve stimulation in isolated guinea-pig vas deferens were potentiated by GUB. GUB specifically antagonized the serotonin-induced contraction of the isolated rat fundus strip and nonspecifically inhibited acetylcholine, histamine or Ba2+-induced contractions of isolated guinea-pig ileum at higher concentrations. GUB exhibited local anesthetic actions and diuretic effects, but had no particular actions on neuromuscular transmission, isolated rat uterus, guinea-pig tracheal muscle and the hematic system. These effects of GUB were found to be almost identical with but less potent than those of CLD. The effects of GUD were basically different from GUB.

Animals↗
PubMed1983

A case of advanced breast cancer associated with hypocalcemia.

Although hypercalcemia is a well-known complication of malignant diseases, hypocalcemia seems to be a rather rare one. A 34-yr-old woman with advanced breast cancer who presented hypocalcemia is described. She had generalized multiple osteolytic bone metastases which were progressive in spite of chemo-endocrine and radiation therapy. She was admitted because of severe bone pain and dyspnea caused by bilateral pleural effusion. Laboratory examination on admission showed that the serum calcium was 9.6 mg/dl, serum total protein 5.9 g/dl, serum inorganic phosphorus 4.6 mg/dl, and serum alkaline phosphatase 29.6 King-Armstrong units. The serum calcium gradually fell to 7.0 mg/dl on the 45th hospital day when the serum total protein was 6.8 g/dl and she complained of paresthesia in the extremities. On the 58th day, severe tachycardia and hypotension developed and she died of congestive heart failure on the 67th hospital day. At that time the serum calcium was 5.4 mg/dl. During her hospital course, the plasma parathyroid hormone levels were examined repeatedly and were 0.4, 0.6, 0.6 and 0.7 ng/ml (normal; less than 0.5 ng/ml). Autopsy revealed that cancer invaded the space between the thyroid and the trachea and no parathyroid glands could be found even in the mediastinum. Microscopically the parathyroid glands were replaced completely by the cancer cells. These observations indicate that metastasis of breast cancer to the parathyroid glands caused relative hypoparathyroidism, resulting in hypocalcemia. In addition, congestive heart failure which was refractory to digitalis and diuretics might have been caused by impaired contractility of the myocardium associated with hypocalcemia.

Adult↗
PubMed1982

Influence of tolerance to and physical dependence on opioid analgesics on cortical evoked potential in rats.

The influence of single and repeated doses of morphine, pentazocine, and chlorpromazine on the latent time of cortical evoked potentials was observed in rats. The evoked potentials were induced by electrical stimulation of the sciatic nerve under the condition of curarization and artificial respiration. The evoked potential consisted of 4 phases. The latent time of the N2 component was prolonged by single dose administration of morphine at 5 mg/kg, s.c., pentazocine at 15 mg/kg, s.c., or chlorpromazine at 2 mg/kg, s.c. The effects of morphine and pentazocine were antagonized by naloxone but that of chlorpromazine was not. By repeated administration of morphine at 5 mg/kg or pentazocine at 15 mg/kg twice daily for 4 weeks, the prolongation of latent time tended to disappear gradually. Further, in these rats the latent time became shorter than that of normal rats after naloxone administration or natural withdrawal for 18 hr. Thus the development of tolerance to and physical dependence on these drugs were demonstrated by recovering and shortening of the latent time, even when withdrawal signs were not apparently observed in the rats' gross behavior. On the other hand, repeated administration of chlorpromazine at 2 mg/kg twice daily for 4 weeks did not produce such shortening of the latent time as was observed with morphine and pentazocine. These results indicate that the evoked potential can serve as a sensitive parameter for observation of the development of tolerance to and physical dependence on opioid analgesics in rats.

Analgesics, Opioid↗
PubMed1982

[Clinical study of preoperative chemotherapy of primary breast cancer. 1. Efficacy of a combined use of CPA (endoxan) and FT-207 (or 5-FU dry syrup)].

In twenty-nine cases of primary breast cancer preoperative treatment using CPA and FT-207 (or 5-FUDS) was performed to determine their efficacy. Daily dose of each anticancer drugs was as follows: CPA 50-200 mg, FT-207 200-600 mg, 5-FUDS 200 mg, p.o.. The total doses were CPA 1.8 g, FT-207 5.0g, 5-FUDS 3.4 g in average. In 11 cases (37.9%) reduction in tumor size was obtained. According to Ohboshi's criteria, over Grade II a effect was seen in 5 cases (17.2%), while Grade III effect was not seen in any of the cases. Effective cases were more frequently observed among those which received CPA at 25 mg/kg or more, or FT-207 (5-FUDS) at 80 mg/kg or more. Main side effects were G. I tract symptoms such as anorexia and nausea. To obtain definitive conclusion on the clinical significance of use of CPA and FT-207 (5-FUDS) as preoperative chemotherapy for breast cancer, further studies are required.

Adult↗
PubMed1982

Fecal mutagens in two Japanese populations with different colon cancer risks.

Human feces from 223 Japanese in Hawaii at high risk for colon cancer and feces from 166 Japanese of northern rural Japan at low risk for colon cancer were shown to contain mutagenic activity under five different test conditions. The first assay, using the Ames TA98 and TA100 Salmonella test, detected ether-soluble mutagens in the presence and absence of rat liver microsomes. Of these, the TA98 direct-acting mutagens are present more frequently in the feces of the high-risk population than the low-risk population at a high level of statistical significance (p less than 0.01). TA98 mutagens activated by rat liver microsomes also occur significantly more frequently in the feces of the Japanese from Hawaii (p less than 0.05). Mutagens detected by TA100 in the presence and absence of rat liver microsomes are not commonly found in either Japanese population. The second bacterial test system used to detect fecal mutagens uses Escherichia coli rec-. This system detects water-soluble fecal mutagens which are also present more frequently in the high-risk population than in the low-risk population (p less than 0.05).

Age Factors↗
PubMed1981

Occurrence of ribitol-containing lipoteichoic acid in Staphylococcus aureus H and its glycosylation.

A ribitol-containing lipoteichoic acid was obtained from the 20,000 x g supernatant fraction of Staphylococcus aureus H by extraction with Triton X-100 followed by fractionation on Sepharose 6B and DEAE-cellulose columns. The purified lipoteichoic acid was composed of phosphate, glycerol, glucose, glucosamine, ribitol, and fatty acids in a molar ratio of 1 : 0.9 : 0.06 : 0.03 : 0.09 : 0.07. Based on the structural analysis of fragments from alkali and HF hydrolysis, the lipoteichoic acid appears to consist of three moieties, namely a ribitol phosphate oligomer, poly(glycerol phosphate) which has about 30 glycerol phosphate units, and beta-glucosyl-beta-glucosyl(1 leads to 1)diacylglycerol. N-Acetylglucosamine was linked to the ribitol residues. The lipoteichoic acid serves as an acceptor of glycosyl moieties from UDP-glucose and UDP-N-acetylglucosamine in the enzyme reaction catalyzed by the membrane preparation. The rate of enzymatic glycosylation was increased by prior treatment of the lipoteichoic acid with N-acetyl-beta-D-glucosaminidase. The glycosylation seems to occur at the ribitol residues of the lipoteichoic acid.

Acetylglucosaminidase↗
PubMed1981

Chemical and biological evaluation of fifteen triticale cultivars.

Fifteen triticale cultivars were chemically analyzed and tested in a feeding trial with weanling rats. Chemical and performance data were statistically analyzed by regressions methods. It was observed that 21 day performance of rats was not correlated to any of several chemical parameters such as dietary lysine, chemical score or essential amino acid index. However, dietary lysine was highly correlated to average daily lysine consumed (r = 0.81) and the latter was correlated to average daily gain (r = 0.63).

Animal Feed↗